There are a lot of misconceptions about DUI law out there, and about how long it takes for alcohol to leave the bloodstream. Often when we talk with clients who have been charged with DUI, they are confused about how they got there. They didn’t drink that much, or they waited an hour or two after drinking, yet their BAC is still far above 0.08. So what happened?

First, you need to know what BAC is. BAC stands for blood alcohol content and it is the measurement of the amount of alcohol in your bloodstream. If you haven’t had anything to drink, your BAC will be 0.00. In Arizona, the legal limit to drive is a BAC of 0.08, or .08 grams of alcohol per 100 milliliters of blood (See A.R.S. 28-1381(A)(2)). Additionally, it is illegal to drive if you are impaired by alcohol to the slightest degree, even if your BAC is below a 0.08 (See A.R.S. 28-1381(A)(1)).

DUI Tucson Arizona

“I didn’t drink that much. How can my BAC be that high? The number must be wrong.”

Very often clients tell us that they “only had two drinks.” But, unless you measure your own alcohol, you can’t be sure how much alcohol is in your drink—especially with mixed drinks. If you’re drinking wine, consider that the size of the average wine pour has become drastically larger in the last 30 years. Go pour yourself 5 ounces in a measuring cup. That’s a standard pour for a glass of wine. Looks small, doesn’t it? The wine pour you’re getting in a restaurant or bar might be 1.5-3 times that size. So, when you think you’ve had two glasses of wine, you may have had six.

Then there are differences in alcohol content. Different wines have different levels of alcohol, as do different beers, and different liquors. For liquor, a serving is generally 1.5 ounces and can still vary widely in alcohol content. Go pour 1.5 ounces in a measuring cup, so you can be shocked at how little it is. Now imagine a mixed drink or specialty cocktail, which are often made with multiple shots of liquor. A standard size martini: 3 shots of liquor. If you drink two martinis at happy hour, you may have had the equivalent of six drinks when you thought you were drinking two and mathematically in the clear.

With the rising popularity of craft beers, beer drinkers can easily forget that alcohol content can vary widely and go far beyond the 5% alcohol of “normal” beers, and get into the double-digits—and even as high as some liquors. Add to that the fact that a pint is more than one serving, and you see the problem with not knowing the math on the quantity and alcohol content of even something as classic as beer.

It is possible, and even likely, that when you thought you had two drinks, you actually had the equivalent of six, or more. This leads to many clients being surprised by their blood alcohol level after it is tested.

“I waited a few hours after I drank to make sure I was fine.”

Even if you think you have a good idea of how much alcohol you consumed, you can’t be sure of how quickly your body will metabolize it—and your BAC can continue to rise for up to three hours after you stop drinking. There are a number of factors to consider when trying to determine your BAC, such as: your weight, when you last ate, and your sex.

And, like in the example above, where you had two martinis—you had at least four drinks. Even if you’re doing the rough math of one drink burning off every hour, unless you’re staying for many hours after you’ve stopped drinking, you might not be in the clear. You may be feeling it far less, but your number can still easily be beyond the legal limit.

“I didn’t feel impaired. I was driving fine.”

Two things here: if you have a well-developed tolerance for alcohol, your BAC can be well over the legal limit while you feel fine, and other people think you’re okay to drive, too. If you’re over a .08 BAC, even if you don’t seem drunk, you’re still in violation of the law. The other thing: alcohol changes people’s perceptions of what they’re capable of, and makes some people think they are doing GREAT, when they are not. It is not uncommon for a client to claim they felt unimpaired, and to claim that they did well on field sobriety tests--- and then we watch the video from the police body camera. It often tells a different story. The lesson is, alcohol might tell you that you are a lot more capable of driving than you are.

“I drank coffee to sober up.”

There is nothing you can drink to metabolize alcohol any faster. Coffee does not lower your BAC. It does, however, add caffeine, a stimulant. The caffeine may make you feel more alert, but it has no impact on your BAC. Likewise, drinking water, eating more, etc., does not lower your BAC any faster. Once you have had alcohol, only time will reduce your BAC.

How long do I wait before driving after drinking?

So, how to avoid getting that DUI? Keep in mind that drinks often contain more alcohol than a person thinks. There are so many variables in calculating blood alcohol that it is extremely difficult for the average person to get a rough calculation of when the alcohol will be gone from their system. Unless you have your own BAC testing device that accurately measures your BAC, don’t try to do the math. Get a taxi, an Uber, a Lyft, a Tipsy Tow, or another 100% sober ride. During the holidays especially, there are several free ride services for those who wish to remain safe and DUI-free. We guarantee that the price of a safe ride home is a tiny fraction of what a DUI will cost you.